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Worlds biggest telescope

  1. Apr 16, 2014 #1
    sir i am taking part in the google science fair with my own design of worlds biggest telescope. my design is given below:-
    we will have a geo stationary satellite, which will revolute around the earth and we will have a big mirror on the earth with focus on the satellite
    when rays will come from infinity they will reflect back and fall on the satellite which will capture them
    is this a right design if it is right and some one wants to help me in my project then contact me:-

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    Last edited by a moderator: Apr 17, 2014
  2. jcsd
  3. Apr 16, 2014 #2


    Staff: Mentor

    This will be a daunting task. The changing temperature, the suns daily trek, the earth tremors and the atmospheric turbulence not to mention the changing weather will all conspire to ruin the view unless you correct for them. Why not construct a massive scope in space with similar dimensions?

    There a science fiction novel called Ringworld where the material of an Earthlike planet is converted into a ring with a diameter the same as earths orbit. The ruing orbits the sun and provides plates that block thee sun to produce nighttime conditions. The Ringworld engineering has been studied for feasibility and may have some relevance to your idea.

    On a smaller scale the international space station and it's engineering challenges may also have some relevance.
  4. Apr 16, 2014 #3


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    You need an enormous primary mirror to capture photons, or multiple small mirrors. It's much easier to build multiple mirrors on the ground and use a computer to keep them properly aligned. This is the modern approach to building giant telescopes. Having the secondary mirror in space gives you a huge f ratio, but, is impractical. Maintaining a usable f ratio would be virtually impossible.
  5. Apr 16, 2014 #4


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    Building big mirrors is a structural nightmare. You'd be better off with the primary mirror in space and the secondary on earth.
  6. Apr 17, 2014 #5
    is there any one to help me in my project

    is there any one to help me in my project
  7. Apr 17, 2014 #6


    Staff: Mentor

    This is your project and you must spearhead its development. Before we can help, you need to show us what you've done and then ask questions on the various pieces of your design, how you intend to fix them and why...

    Part of your project is documenting what you thought about, the engineering problems you've encountered, the proposed solutions and the solution you've chosen. At each step, new challenges will arise and you will need to address them.

    I imagine you will also need to construct a model to showcase your design.

    This should be a lot of fun.

    Another engineering project that might be of interest and relevant to your project is the space elevator:


    and here's another article on megascale-engineering that may be relevant for the large scale construction:

  8. Apr 17, 2014 #7


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    Hey, what do you think the replies so far have BEEN doing??? As jedishrfu said, show us some work of your own, don't just ask us to do it for you. That's not how this forum works. As he also said, this should be a neat project. Get to work :smile:
  9. Apr 18, 2014 #8
    i dont know how to calculate different parameters of a reflecting telescope like light gathering power etc.
  10. Apr 18, 2014 #9


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    OK, what DO you know? What CAN you do to get the project started? If you are going to have to rely on others for absolutely everything then you might want consider that you have taken on more than you can handle.

    What I would suggest is that you at least make a concise list of what you think are the most important factors involved in solving this problem and then add to it a brief statement of what you know about each of these factors and what you feel you still need to know, and based on that list decide how to next proceed.

    You have got to do SOMETHING to get yourself organized on this other than just asking other for help without saying exactly what you know and what you need to know. And if you really don't know anything about any of it, how are you going to deal with that?
  11. Apr 18, 2014 #10


    Staff: Mentor

    To start the discussion why not describe why you chose a reflector design from the several designs that are available. This link shows the most common telescope designs used today:


    Basically you can do a simple cost bennefit analysis on the designs. You should keep a journal of everything you're doing and when so that you'll have something to show and reference as you progress along the project:

    Day 1: Describe the project

    Day 2: Select a telescope design list pros and cons of all designs considered

    Day 3: Having selected a design explore the details of the design like placement of components, type of material and associated costs...

    Day 4: Do some googling to learn more about telescopes and how they work

    Day 5: ...

    You must imagine you are an experienced engineer and you have only so many days to complete your task. You must be serious about the project like you're trying to sell it to people on Kickstarter and you need the money from your campaign to build it. Many great building projects go through this kind of cycle.

    As I mentioned earlier look at the ringworld example. Its an imaginary project that many engineers and physicists got interested in when the science fiction book came out. They wanted to see if it really could be built, how much material was needed and the various engineering challenges they would need to overcome. A telescope of the size you're describing would have similar challenges and the more you can identify and even solve the more impressed your teacher will be.

    This really should be an exciting project so don't procrastinate.
    Last edited: Apr 18, 2014
  12. Oct 11, 2014 #11

    Will you let us know how the project fared?

    If the earth is too unforgiving a place for this telescope, why not build one on the moon? This way, the difficulties involved in construction could get worked out before starting on the earth based telescope.

    And remember, whether it's the Earth or the moon, it might use a robotic cleaning system like this:


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